The present invention relates to novel condensation polymers having sulfur in the polymer backbone.
Organic compounds containing sulfur are well-known in the art, and exhibit a wide variety of desirable properties. See, for example, Preparative Methods of Polymer Chemistry, 2nd Ed., Wayne Sorenson and Tod Campbell, page 183, Interscience Publishers, 1968. See also page 36-37 of Polymeric Sulfur and Related Polymers, Arthur Tobolsky and William MacKnight, 1965, published by John Wiley and Sons, Inc. In particular, polymers containing bicyclic organic compounds and sulfur are prepared for use as films or coatings as taught in U.S. Pat. No. 3,586,700. Unfortunately, such polymers exhibit poor char formation properties. In addition the pendant bicyclic compound is connected to the polymer backbone through two bonds, yielding a product which does not exhibit good flexibility.
In view of the deficiencies of the prior art, it would be highly desirable to provide a polymer having sulfur in its backbone which is easily prepared using readily available starting materials, and which exhibits excellent char formation properties and a wide range of glass transition temperatures.